Mr. R. I. Pocock on the Equidfc. 305 



concealment, and lost where their suppression was demanded 

 for the same object. Their slight systematic importance 

 is sliown by their extreme variation within the limits of the 

 group termed " Burchell's zebras " — a group composed of 

 forms admittedly related to one another. Tiieir disappearance 

 in such forms as the African " asses " {E. tceniopus and 

 somaliensis) and Asiatic "asses" {E. hemwnus, onager, and 

 hemippus) is in itself no proof of kinship close enough to 

 justify the union of these two sections of the Eqiiid^ into a 

 group equivalent to one embracing the striped species. 



The stripes of the Equidai in fact appear to be strictly 

 comparable to the stripes or spots of the Felidaj and to have 

 much the same taxonomic value. No one, presumably, 

 would feel justified in establishing a genus for the tawny or 

 fawn-coloured cats, like tlie lion, puma, caracal, jaguarundi, 

 &c., on the strength of their uniform coloration, and another 

 for those species of Felis in which the primitive variegated 

 markings persist, 



Hejecting, then, for these reasons the suppression or reten- 

 tion of body-stripes as a basis for the classification of those 

 existing species of Equidaj which have warts only on the 

 fore legs, a short erect mane, and a tufted tail, I think these 

 species may be classified under the following headings: — 



1. GeeVy's Zebkas (Equus Grevyi). — One species with 



the two subspecies described below. 

 That Grevy's zebra stands apart from the other striped 

 species has been already pointed out (Ann. & Mag. Nat. 

 Hist. (6) XX. pp. 48-49, 1897). The arrangement of stripes 

 on the hind-quarters is unique; the warts on the fore legs 

 are abnormally small, and the extension of the mane over the 

 withers sharply differentiates this species from those of the 

 following section, to which E. Grevyi is commonly supposed 

 to be nearly related. Lastly, the widely expanded rounded 

 ear is quite peculiar and contrasts forcibly with the longer or 

 shorter, but narrow, fusiform, and pointed ear of other 

 Equidse. 



2. Afbican Wild Asses and Mountain Zebras {Asinus). 



a. E. asinus. 



a. Subsp. toimopus. 

 /3. „ somaliensis. 



b. E. zebra. 



a. Typical subspecies. * 



B. Subsp. Hartmannce.') r> , -i x- i 



^ p • . >- i erliaps identical. 



7. „ Fenricet. ) ^ 



